The enzyme is found in several bacterial strains which use the reverse reaction to degrade N-acetylneuraminic acid (sialic acid).The forward reaction is particularly useful for the determination of sialic acid concentrations by quantitatively converting it to N-acetylmannosamine and pyruvate.

Since sialic acid is both negatively charged and a non-reducing sugar, its direct analysis is more difficult than conventional sugars. N-acetylmannosamine, however, can be assayed as a conventional reducing sugar by various techniques such as flourescent dye or radioactive labeling.

Alternatively, the pyruvic acid generated in the reaction can be assayed using enzymes such as Lactic Dehydrogenase, coupled to NADH oxidation, to reduce pyruvate. NADH oxidation can be spectrophotometrically quantitated. Another method uses pyruvate oxidase to generate hydrogen peroxide which is measured colorimetrically.

In addition to free neuraminic acid, N-acetylneuraminic Acid Aldolase can be used to determine the total amount of neuraminic acid in:

Glycoproteins

Cell surfaces

Polysialic acids

Capsular Polysaccharides (consisting only of polysialic acid)

by first digesting the whole cells, glycoprotein or polysaccharide with QA-Bio Sialidase Au (E-S001), and then determining total N-acetylneuraminic acid